Pertussis toxin (PT) is produced by Bordetella pertussis is a main component in all vaccines against whooping cough. PT is typically combined with tetanus and diphtheria toxoids. Industrial production of PT is typically achieved by cultivating B. pertussis in defined media. PT is then isolated from the supernatant and purified by using the well-known techniques (i.e., U.S. Pat. Nos. 6,399,076; 5,877,298; and, Sekura, et al. J. Biol. Chem. 258:14647-14651, 1983; Bogdan, et al. Appl. Env. Micro. 69(10): 6272-6279, October 2003). The majority of known methods each require the use of matrix-bound bovine fetuin (BF) or asialofetuin, the source and purity of which is critical. The use of bovine-derived reagents has led to some concern over bovine-related diseases such as bovine spongioform encephalopathy (BSE).
Those of skill in the art have therefore desired a method for purifying PT that does not rely on BF. One such method is described by Bogdan, et al. (Appl. Env. Micro. 69(10): 6272-6279, October 2003) Peptides having the ability to mimic the glycosidic moiety of bovine fetuin by binding to PT were identified using a phage display system. Three peptides (3G5: NGSFSGF (SEQ ID NO: 1); 3G8: NGSFSGC (SEQ ID NO: 2); and, 3G2: DGSFSGF (SEQ ID NO: 3) having the consensus sequence XGSFSGX (X is any amino acid: SEQ ID NO: 4) were identified as having PT-binding capacity. 3G2 was also utilized in an affinity column to purify PT from a partially purified PT preparation.
Additional methods for designing and utilizing peptides to purify PT in the absence of bovine products are desired by those of skill in the art. Provided herein are reagents and methodologies for affinity purification of PT without the use of fetuin in any form.